Collaborative Research: What are the causes and consequences of reproductive cooperation between unrelated male fish?

University Of California-Santa Cruz, Santa Cruz CA

Investigators

Abstract

Interactions between organisms can take a variety of forms, from competition and conflict to cooperation. While cooperation among relatives is both well documented and relatively well understood in everything from slime molds to primates, cooperation among unrelated individuals, especially those that also compete directly with one another, remains more puzzling. The proposed research will study what social and environmental factors cause unrelated male marine fish to either cooperate or compete with one another. This research will also identify the genes, brain regions and hormones that control these behaviors - currently, there is little specific information on these mechanisms - and measure how cooperative versus competitive interactions affect reproduction in this species. Understanding what shapes cooperation, competition and conflict is not only of general interest, but can also inform conservation and management because negative interactions such as conflict and competition have been shown to increase a species risk of extinction. This project supports the training of undergraduate and graduate students on a variety of biological methods including field research on marine fish and tools for understanding the genes underlying social behavior. The professors and students involved in this research will also offer internships to high school students, education outreach lectures and online activities aimed at women and girls interested in science fields and careers. Several involved students will be from an undergraduate-focused institution which draws a number of non-traditional STEM students which will allow these students direct training opportunities that they otherwise would not have access to. The long-term goal of our research is to understand how social interactions and selection interact to shape variation in reproductive behaviors. We aim to quantify male plasticity in social behavior, document neural and hormonal mechanisms underlying plasticity in male social behavior, and determine how variation in male social interactions affects selection. To address these aims, we propose research on wild-living ocellated wrasse (a marine fish, Symphodus ocellatus). Ocellated wrasse males exhibit three alternative reproductive types: 'nesting males' provide parental care, defend territories, and form cooperative associations with unrelated 'satellites', who cheat by sneaking fertilizations but help by reducing reproductive competition from 'sneakers' (who do not cooperate or provide care; Stiver & Alonzo 2013). We adopt an integrative approach that allows us to examine the reproductive fitness consequences of variation in cooperation and competition and identify neural and hormonal mechanisms underlying this variation and behavioral plasticity.